Material working apparatus



Feb. 6, M J, SEAGREN MATERIAL WORKING APPARATUS Filed July 9, 1937 Patented Fels. 6, v1940 rettet. OfFF-ICr;,y1v

e 2,189,086 l MATERIAL WORKING APPARATUS Martin Seagren, Chicago, Ill., assignornto Western Electric Company, Incorporated, New

York, N. Y.,"a corporation of New York Application Juvly 9, 1937,v serial No. 152,735- iclaim. (ci. 164-59) This invention relates to material Vworking apparatus, and more particularly to material stop devices for material working apparatus, such as punching and shearing presses. t t

An' object of this invention is to provide an effective andsimple material stop device capable of yielding when the material being Worked close to its edge, abutting the stop device, bulges, thus preventing the misalignment ofthe cooperating Working tools and consequent damage thereto.

' In accordance withone embodiment of this invention as used in connection witha material punching apparatus Y' employing a reciprocative "punch and cooperating stationary die .member for working heavy stockv or parts, thereis provided a spring pressed stop device for positioning the forward edge of the stock, the stop device being capable of yielding as the material ofthe stock bulges when being worked close to its edge abutting the stop device, the movement of the stop device preventing the forcing or bending of the punch out of register with its dieand subse- `1 quent breakage thereof. The spring pressed stop device may also serve asan ejector for the worked part from the apparatus as the punch is retracted. Other objects and advantages of this invention will morejfully appear from the following detailed description, taken in connection with the accompanying drawing, ywherein Fig. 1 is a diagrammatic fragmentary elevational view, partly in section, of a material working apparatus comprising a reciprocative punch h and cooperating stationary die showing the yieldable material stop device embodying the invention applied thereto, and i. Fig. 2 is a plan view thereof with the movable punch removed. I

Referring now to the drawing, the stop devic embodyingthe features of this invention has been shown, for example, applied to a metal strip or part perforating machine which may be of any suitable type, for instance, a punch press.v Since it is not essential to a `complete understanding of the invention, the-machine has not been illustrated, except those parts directly concerned with the invention, which comprise the following:

A vertical reciprocative platen I0 carrying a perforating punch II and a cooperating stationary die bed I2, the die bedv II, having an opening I4 which is of similar shape to that of the material to be punched or shear-ed from'l a metal strip or part indicated at I'I, The punch I I which also conforms to that ofthe material to be sheared from the part I1 is shaped to vsuitably flt in the die opening I4 whereby in a down- -Fixed in a suitable manner (not shown)l to the vof the metal betweenv the rigidvstop and the `ness and distance having been found by experiupper surface of the die `bed I2`is a stripper plate I9 formed with va'channel Ztl'in its bottom surface serving to guide the strip or part 'I'I lon' the die bed I2 into position under the punch I I which is in an elevated position at this time. An aperture `2l is provided in the stripper plate I9. for the free passage therethrough of the punch II during its reciprocation. In an upward movement of the punch II after its operation on the part I'I, it will be obvious that the plate I9 will strip the part therefrom. y

The stop device embodying the features of this invention for positioning the forward or leading in edge of the part I'I relativeto the cooperating punch II and die opening I4 and thereby deter- `mining the location of the perforation relative to the leading in edge of the part comprises a bar y r2,5 reciprocably carried on a pair of headed pins 26 threaded at` their inner ends intothe` right end of the stripper plate. Surrounding each of the pins 26 between the inner faces of the heads thereofand the outer end of the bar 25 is a compression spring 21 which acts totnormally maintain the stop bar in abutting relation with the end ofthe stripper plate as shown in' full lines in the drawing. Although in the present application of the stop bar 25 it has been described and illustrated as being carried on andv engaging the stripper plate it will be obvious that it could be otherwise mounted.

t In working a metal strip or part, such as' I1 of relativelygreat thickness, close to its forward orA leading in edge difculty is experienced when a rigid stop is used due t0 the. distortion or bulging punch and die members.` The bulging of the metal causes a misalignment of the punch and die members, the punch being forced or bent out of register with the die vopening and finally causing the breakage of these parts.

In setting up the apparatus preparatory to working a metal strip or part of a certain` thickness withthe work being performed a predetermined distance from its forward edge, such vthickence to be such that a bulging ofthe metal between the punch II and the stop bar 25 will occur, suitable springs are installed on the headi' ed pins 26 which will permit the bar to vyield sufciently as the bulging of the metalv occurs so that 5g v curved broken line 28 (Fig. 2) between the punch and the abutting surfaces of the part being Worked and the stop bar 25 causes the bar to yield and it moves outwardly on the pins 26 against the resisting force of the compression springs 21 to the position indicated by the broken lines 29. Thus no appreciable lateral force is exerted on the punch H or die bed I2 tending to bend or force them out of register. During the retraction of the punch Il the perforated` part I1 is stripped from the punch by the stripper plate I9 and as the partis freedr from'the punch the energy stored in the compression springs 2 is suddenly released and the resultant movement of the stop bar 275 to its normal stop position abutting the stripperr plate serves to eject the worked part i1 from the apparatus. v

From` the foregoing description it will be apparent that an effective and simple material stop device is provided for material punching apparatus which is capable of .yieldingupon the material between the cooperating punch and die members and the stop'devioe being distorted in; I

the manner above described, thus preventing the misalignment and breakage of the punch and 4die members. `Further, that the resilient stop' device may also serve as an ejector for the Worked ma'- terial from the apparatus as `the punch is retracted.

It Will be understood that the embodiment herein described is merely illustrative of the inl vention and on'e applicationY thereof, the inven.

tion being limited 'only by the scope of the appended claim. l

= Whatisciaimedisz. 7 l

In an apparatus for Working heavy'metalstock or parts close toan edge thereof, a reciprocative punch, a cooperating-die member aligned with the punch, and a stop device for the part against 'y which the. same is abutted in positioning the part to bey Worked comprising a reciprocably mounted bar, 'an abutmentfor maintaining said bar in ar predetermined stop position, andresilient means,`

eective Ito constantly urge saidbar against ,said

abutmentfbut permitting' thebartomove along a rectilinear line solely in'response to a bulgingv -of the'part atqsaid edgethereof'duringthe Work-V` ing kof the" part 'to prevent deformation ofthe punch.

J.y SAGRE. l l 

